Field of the Invention
The present invention relates to a pneumatic tire.
Discussion of the Background
Rolling resistance of tires is mainly caused by energy loss involved in cyclic straining of rubber during tire running. A conventional attempt to alleviate rolling resistance is to use rubbers of low levels of energy loss (that is, with smaller tan δ) for the tread rubber, which undergoes a large amount of straining during tire running and a large amount of rubber consumption. However, the use of rubbers of low levels of energy loss alleviates rolling resistance at the compromise of grip performance (in particular, wet grip performance), and wear resistance may also deteriorate.
As disclosed in Japanese Unexamined Patent Application Publication Nos. 2004-010781 and 2004-002622, studies are underway to find a tread rubber composition that alleviates rolling resistance while improving wear resistance. However, the rubber composition approach alone makes a limited contribution to improved wear resistance and low rolling resistance. Thus, there is a strong demand for another approach, instead of the rubber composition approach, to improved wear resistance and low rolling resistance.
It is an object of the present invention to provide a pneumatic tire with alleviated rolling resistance and alleviated uneven wear at the shoulder of the pneumatic tire.